Electric power steering systems are used in motor vehicles to reduce the effort required to turn the steering wheel as an alternative to more conventional hydraulic power steering systems. In the conventional electric power steering systems, the motor drive power cables extend from the battery to a power unit placed in the passenger compartment, and further extend to the electric actuator for the power steering system. Therefore, the overall length of the motor drive cables is relatively long, and the cables are typically bundled with other electric cables which may include signal lines.
In such a wiring arrangement, the voltage drop due to the electric resistance of the motor drive power cables is a problem particularly because the power steering system consumes a relatively large electric current. Thus, a relatively large electric motor is required to compensate for the voltage drop or the diameter of the motor drive power cables has to be increased to achieve a sufficient power output in the power steering system. In either case, the cost increases. The large current flowing in the motor drive power cables may cause electromagnetic interferences to adjacent signal lines, and it is therefore desirable to minimize the length of the power cables for this reason as well.